Manipulation device

ABSTRACT

A manipulation device has a manipulation body operated by the manipulator in a manipulation direction, a support body freely supporting the operation of the manipulation body, and a movable load imparting mechanism imparting a load to the manipulation body. The movable load imparting mechanism has a movable member engaged with the movable axis of the manipulation body, a magnetism generating mechanism having a coil that generates a magnetic field and a first yoke provided so as to enclose the coil, and a magnetic viscous fluid, its viscosity changing according to the strength of a magnetic field. The magnetic viscous fluid is filled in a first gap between the first yoke and the movable member. In the gap, a first buffering layer not harder than the movable member is provided on at least one of the opposing plane of the first yoke and the opposing plane of the movable member.

CLAIM OF PRIORITY

This application is a Continuation of International Application No. PCT/JP2017/005256 filed on Feb. 14, 2017, which claims benefit of Japanese Patent Application No. 2016-036429 filed on Feb. 26, 2016. The entire contents of each application noted above are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a manipulation device that can give a manipulation feeling to a manipulator in response to a manipulation by the manipulator.

2. Description of the Related Art

Recently, various manipulation devices with a force feedback function are proposed. When the manipulator manipulates a manipulation member, these various manipulation devices impart an external force (sense of force) such as a resistance force or thrust that matches the amount of manipulation of the manipulation member and its manipulation direction so that a manipulation feeling can be made superior and a desired manipulation can be reliably performed. In particular, in the manipulation of a vehicle-mounted control device such as for air conditioning, audio, or navigation, blind manipulation is often performed, rather than manipulation performed while the control device is viewed, so imparting a sense of force to the manipulation member (manipulation knob) has been effective from the viewpoint of safety as well.

A manual input device 800, for use in an automobile, that uses the manipulation device as described above, is proposed in Japanese Unexamined Patent Application Publication No. 2003-50639 (cited as a first conventional example). FIG. 10 is a longitudinal cross-sectional view of the manual input device 800 in the first conventional example, illustrating the main elements in the basic structure of the manual input device 800.

The manual input device 800 illustrated in FIG. 10 includes a knob 880 (manipulation member) that is rotated by being manually manipulated by the operator (manipulator), a planetary gear mechanism having a carrier axis 851 provided integrally with the knob 880, a cylindrical ring gear case 860 (fixing member) that constantly fixes a ring gear 862 in the planetary gear mechanism, a motor 810 having an output axis 811 engaged with a sun gear 832 in the planetary gear mechanism, an encoder 830 (detection means) that detects the rotation of the output axis 811 of the motor 810, and a control means that controls the rotation of the motor 810 according to the result of detection by the encoder 830. To give a predetermined manipulation feeling to the manipulator, the manual input device 800 rotates the motor 810 at a predetermined timing, and transmits this rotational force to the knob 880 through the planetary gear mechanism.

Although this manual input device 800 can give a superior manipulation feeling, however, the use of the motor 810 has made it difficult for the manual input device 800 to meet a demand for further downsizing. In view of this, a method has been explored by which an external force (sense of force), such as a resistance force or thrust that matches the amount of manipulation of the manipulation member and its manipulation direction, has been exploded without using the motor 810.

In Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2005-507061 (cited as a second conventional example), a manual brake 911 is proposed that uses a magnetic field responsive material (magnetic viscous fluid) the fluidity of which is affected by a magnetic field generating means. FIG. 11 is a cross-sectional view of the manual brake 911 in the second conventional example in the longitudinal direction.

The manual brake 911 illustrated in FIG. 11 includes a housing 913 having a first housing chamber 915 and a second housing chamber 917, a closing plate 919 that covers the open end of the housing 913, a shaft 923 that passes through the second housing chamber 917 and extends to the first housing chamber 915, a rotor 921 that is provided integrally with the shaft 923 at its end and is disposed in the first housing chamber 915 in parallel with the closing plate 919, a magnetic field generator 929 that is provided in the first housing chamber 915 in the immediate vicinity of the outer periphery of the rotor 921, a magnetic responsive material 941 that is filled in the first housing chamber 915 so as to enclose the rotor 921, and a control means 925 that is provided in the second housing chamber 917 and controls and monitors a brake operation. The magnetic field generator 929 has a coil 931 and a pole piece 933 (yoke) disposed so as to enclose three sides of the coil 931.

When the coil 931 is energized, a magnetic flux J37 illustrated in FIG. 11 by broken lines is generated. Along with the generation of this magnetic flux J37, soft magnetic or magnetizable particles in the magnetic responsive material 941 are arranged along the magnetic flux J37. Thus, resistance to be given to the rotor 921 by the magnetic responsive material 941 is increased in a direction in which this arrangement is cut, that is, the rotational direction of the rotor 921, which rotationally operates. Accordingly, the manual brake 911 has a brake effect that stops the rotational operation of the shaft 923 by using this magnetic responsive material 941 and rotor 921.

SUMMARY OF THE INVENTION

By using the effect of the magnetic responsive material 941 (magnetic viscous fluid) described above, a method of imparting an external force (sense of force), such as a resistance force or thrust that matches the amount of manipulation of the manipulation member and its manipulation direction, without using a motor can be considered. In the structure in the second conventional example, however, there has been the fear that the rotor 921 abuts the coil 931 or pole piece 933 (yoke) due to the rotation of the rotor 921 and thereby a contact sound, a sliding sound, and the like is generated. Therefore, there has been the problem that annoyance or the like is given to the manipulator and manipulation feeling is worsened. A possible solution to prevent rotor 921 from abutting the coil 931 or pole piece 933 is to widen a gap between the rotor 921 and the coil 931 and pole piece 933. However, to change the viscosity of the magnetic viscous fluid filled in the widened gap, a large magnetic field is needed. Therefore, the coil that generates that magnetic field and the yoke that induces the magnetic field must be enlarged, so there has been another problem that belies the purpose of achieving downsizing.

The present invention addresses the problem described above by providing a manipulation device that uses a magnetic viscous fluid so that a superior manipulation feeling is obtained.

To solve this problem, the manipulation device in the present invention has a manipulation member with a manipulation body that operates in a manipulation direction according to a manipulation by a manipulator, a support body that freely supports the operation of the manipulation body, and a movable load imparting mechanism that imparts a load to the manipulation body. The manipulation body has a movable axis that enables the operation. The movable load imparting mechanism has a movable member that performs the operation by being engaged with the movable axis, a magnetism generating mechanism that faces the movable member with a gap intervening therebetween, and a magnetic viscous fluid present in at least part of the gap, the viscosity of the magnetic viscous fluid changing according to the strength of a magnetic field. The magnetism generating mechanism has a coil that generates a magnetic field by being energized, and also has a first yoke disposed on one side of the movable member so as to enclose the coil. The magnetic viscous fluid is filled in a first gap, which is the gap between the first yoke and the movable member. In the gap, a first buffering layer having hardness lower than that of the movable member is provided on at least one of the opposing plane of the first yoke and the opposing plane of the movable member.

According to this, in the manipulation device in the present invention, a magnetic field is generated due to energization to the coil, a magnetic path is formed so as to spread from the first yoke toward the movable member, and thereby magnetic particles in the magnetic viscous fluid are aligned along a magnetic flux. Thus, a load is applied by the magnetic viscous fluid to the movable member, which operates in a direction crossing a magnetic flux formed from the first yoke to the movable member and from the movable member to the first yoke, so a load is applied to the manipulation body through the movable member and movable axis. Even if the movable member abuts the first yoke when the movable member operates, an abutting sound, a sliding sound, and the like are reduced. Due to these, a superior manipulation feeling can be given to the manipulator for a manipulation by the manipulator.

In the manipulation device in the present invention, the movable member is preferably formed from a soft magnetic material.

According to this, a magnetic path is reliably formed from the first yoke to the movable member and from the movable member to the first yoke, and thereby magnetic particles in the magnetic viscous fluid are aligned in an opposing plane direction in which the first yoke and movable member face each other. Thus, a stronger load is applied to the movable member, which operates in a direction crossing the opposing plane direction in which the magnetic particles are aligned. Due to this, a stronger load is applied to the manipulation body through the movable member, and movable axis and a more superior manipulation feeling can be given to the manipulator.

In the manipulation device in the present invention, the magnetism generating mechanism preferably has a second yoke disposed on another side of the movable member so as to face the movable member.

According to this, a magnetic path is reliably formed from the first yoke to the second yoke and from the second yoke to the first yoke. Thus, magnetic particles can be aligned in a direction perpendicular to the direction in which the movable member operates, so a stronger load can be applied. Due to this, a stronger load can be applied to the manipulation body through the movable member and movable axis.

In the manipulation device in the present invention, the magnetic viscous fluid is preferably filled in a second gap, which is the gap between the movable member and the second yoke.

According to this, since the magnetic viscous fluid is filled in the second gap between the second yoke and the movable member, a further load can be imparted to the movable member, which operates in a direction crossing the magnetic flux. Due to this, even in an equivalent magnetic field, a further large manipulation feeling can be given to the manipulator.

In the manipulation device in the present invention, the first buffering layer is preferably formed from a magnetic sheet.

According to this, the magnetic flux generated by the coil can be led from the first yoke to the movable member. Due to this, a further load can be imparted to the movable member, which operates in a direction crossing the magnetic flux.

In the manipulation device in the present invention, the first buffering layer is preferably a synthetic resin sheet including magnetic powder.

According to this, the magnetic flux generated by the coil can be led from the first yoke to the movable member. Therefore, a further load can be imparted to the movable member, which operates in a direction crossing the magnetic flux. In addition, since the base of the first buffering layer is formed from a synthetic resin material having lower hardness, an abutting sound, a sliding sound, and the like are further reduced. Due to these, a more superior manipulation feeling can be given to the manipulator for a manipulation by the manipulator.

In the manipulation device in the present invention, at least one of the second yoke and movable member preferably has a second buffering layer having hardness lower than that of the movable member.

According to this, since at least one of the second yoke and movable member has the second buffering layer having hardness lower than that of the movable member, even if the movable member abuts the second yoke when the movable member operates, an abutting sound, a sliding sound, and the like are reduced. Due to this, a superior manipulation feeling can be given to the manipulator for a manipulation by the manipulator.

In the manipulation device in the present invention, the second buffering layer is preferably formed from a magnetic sheet.

According to this, the magnetic flux generated by the coil can be led from the first yoke to the second yoke. Due to this, a further load can be imparted to the movable member, which operates in a direction crossing the magnetic flux.

In the manipulation device, the second buffering layer is preferably a synthetic resin sheet including magnetic powder.

According to this, the magnetic flux generated by the coil can be led from the first yoke to second yoke. Therefore, a further load can be imparted to the movable member, which operates in a direction crossing the magnetic flux. In addition, since the base of the second buffering layer is formed from a synthetic resin material having lower hardness, an abutting sound, a sliding sound, and the like are further reduced. Due to these, a more superior manipulation feeling can be given to the manipulator for a manipulation by the manipulator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of a manipulation device according to a first embodiment of the present invention;

FIG. 2 is an exploded perspective view of the manipulation device according to the first embodiment of the present invention;

FIG. 3A is a top view of the manipulation device according to the first embodiment of the present invention when viewed from the Z1 side indicated in FIG. 1, and FIG. 3B is a front view of the manipulation device when viewed from the Y2 side indicated in FIG. 1;

FIG. 4 is a cross-sectional view of the manipulation device in the first embodiment of the present invention, taken along line IV-IV indicated in FIG. 3A;

FIG. 5 is an enlarged cross-sectional view, at a portion V indicated in FIG. 4, of a movable load imparting mechanism in the manipulation device according to the first embodiment of the present invention;

FIG. 6A is a top perspective view of the movable load imparting mechanism in the manipulation device according to the first embodiment of the present invention, and FIG. 6B is a front view of the movable load imparting mechanism when viewed from the Y2 side indicated in FIG. 6A;

FIG. 7A is a bottom perspective view of the movable load imparting mechanism in the manipulation device according to the first embodiment of the present invention, the second yoke illustrated in FIGS. 6A and 6B being omitted, and FIG. 7B is also a bottom perspective view of the movable load imparting mechanism, the movable member illustrated in FIG. 7A being further omitted;

FIG. 8A illustrates a magnetic viscous fluid in the manipulation device according to the first embodiment of the present invention in a state in which a magnetic field is not applied, and FIG. 8B illustrates the magnetic viscous fluid in a state in which a magnetic field is applied;

FIG. 9 illustrates the movable load imparting mechanism in the manipulation device according to the first embodiment of the present invention, the drawing being a graph representing an example of a relationship between a current flowing in a magnetic field generating mechanism and torque applied to a manipulation body;

FIG. 10 is a longitudinal cross-sectional view of a manual input device in a first conventional example, illustrating the main elements in the basic structure of the manual input device; and

FIG. 11 is a cross-sectional view of a manual brake in a second conventional example in the longitudinal direction.

DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present invention will be described with reference to the drawings.

First Embodiment

FIG. 1 is a top perspective view of a manipulation device 100 according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the manipulation device 100. FIG. 3A is a top view when viewed from the Z1 side indicated in FIG. 1, and FIG. 3B is a front view when viewed from the Y2 side indicated in FIG. 1. FIG. 4 is a cross-sectional view taken along line IV-IV indicated in FIG. 3A.

The manipulation device 100 in the first embodiment of the present invention has an appearance as illustrated in FIGS. 1 and 3. As illustrated in FIG. 2, the manipulation device 100 is mainly structured by having a manipulation member 1 with a manipulation body 11 that operates in a manipulation direction due to a manipulation by the manipulator, a support body 3 that freely supports the operation of the manipulation body 11, a movable load imparting mechanism F5 that imparts a load to the manipulation body 11, and a first buffering layer K16 and a second buffering layer K26 that are used to improve a manipulation feeling. The manipulation device 100 in the first embodiment of the present invention is a rotatable manipulation device that can be manipulated so as to swing (rotate) in a swinging direction (rotational direction), the rotation being centered around the movable axis 11 j (see FIG. 2) of the manipulation body 11.

In addition to the constituent elements described above, the manipulation device 100 in the first embodiment has a side-wall spacer S17 (see FIG. 2), which forms part of the side wall of the main body, and a slit spacer S57 (see FIG. 4) disposed in the movable load imparting mechanism F5. With this rotation-type manipulation device 100, the manipulation part (not illustrated), such as a manipulation knob or a manipulation control, of the manipulation member 1 is engaged with one-end of the manipulation body 11. The manipulation part is grasped and manipulated by the manipulator, and the manipulation body 11 rotationally operates in both directions.

If this manipulation device 100 has a rotation detection means (not illustrated) that detects the rotational operation of the manipulation body 11 (for example, the rotational angle of the manipulation body 11), the manipulation device 100 can be used as a rotation type of input device that can input a rotational angle. If a so-called rotation-type variable resistor that is formed with a substrate on which a resistive element pattern is formed and a slider that makes a sliding contact with the resistive element pattern, for example, is used as this rotation detection means, when this rotation-type variable resistor is engaged with the manipulation body 11, the rotational operation of the manipulation body 11 can be easily detected. The rotation detection means is not limited to a rotation-type variable resistor. For example, the rotation detection means may be a magnetic angle detection detecting device that uses a permanent magnet and a magnetism detecting sensor.

First, the manipulation member 1 of the manipulation device 100 will be described. The manipulation member 1 has a manipulation part (not illustrated) that the manipulator grasps, and also has the manipulation body 11 that operates along with the rotational manipulation of the manipulation part when the manipulation part is engaged.

The manipulation part of the manipulation member 1 is a member, such as a manipulation knob or a manipulation control, that is grasped and manipulated by the manipulator. When the manipulation part is to be used, it is engaged with one end of the manipulation body 11. As the shape of the manipulation part, an easy-to-manipulate shape or the like is considered. The shape of the manipulation part is arbitrarily determined depending on the product to which the manipulation part is applied.

As illustrated in FIG. 2, the manipulation body 11 of the manipulation member 1 has a columnar part 11 c having a cylindrical shape, the movable axis 11 j that passes through the center of the columnar part 11 c and has a center at the center of rotation, and a ring part 11 r provided at another end of the manipulation body 11, the ring part 11 r being one size larger than the columnar part 11 c. These elements of the manipulation body 11 are manufactured by being injection molded integrally with a synthetic resin such as poly butylene terephthalate (PBT). As illustrated in FIG. 4, an O-ring R7 is placed on the columnar part 11 c and is disposed at a linkage portion between the columnar part 11 c and the ring part 11 r. The O-ring R7 attached to this portion also has a function that closes an accommodation space in which a movable member 55 is accommodated. This prevents a magnetic viscous fluid 75 filled in this accommodation space from leaking from the accommodation space.

Next, the support body 3 of the manipulation device 100 will be described. As illustrated in FIG. 4, the support body 3 mainly includes a bearing part 3 j to which an end of the movable axis 11 j of the manipulation body 11 is abutted, an axis supporting part 3 s into which the columnar part 11 c of the manipulation body 11 is inserted and that guides the columnar part 11 c, and a lid part 3 u that presses the axis supporting part 3 s to stabilize it. The support body 3 supports the manipulation body 11 (part of the manipulation member 1) so that the movement (rotation) of the manipulation body 11 becomes free.

The bearing part 3 j of the support body 3 has a concave shape on a side facing the movable axis 11 j of the manipulation body 11, as illustrated in FIG. 4. When the manipulation device 100 has been assembled, an end of the movable axis 11 j abuts this concave part of the bearing part 3 j. Then, the bearing part 3 j allows the operation of the manipulation body 11 to be easily performed.

The axis supporting part 3 s of the support body 3 has a ring shape having a through-hole at the center (see FIG. 2). As illustrated in FIG. 4, the axis supporting part 3 s is accommodated in a concave part (see FIG. 6A referenced later) formed in the upper part at the center of the movable load imparting mechanism F5 (specifically, an upper yoke 15A of a first yoke 15 included in a magnetism generating mechanism FM5 described later). When the cylindrical part 11 c of the manipulation body 11 is inserted into the through-hole in the axis supporting part 3 s, the axis supporting part 3 s rotatably supports the cylindrical part 11 c (part of the manipulation body 11).

The lid part 3 u of the support body 3 is shaped like a flat plate, the shape being a circular shape having a through-hole at the center (see FIG. 2). The lid part 3 u is placed on the movable load imparting mechanism F5 (specifically, the upper yoke 15A), as illustrated in FIG. 3A. The columnar part 11 c of the manipulation body 11 is inserted into the through-hole in the lid part 3 u, as is the axis supporting part 3 s. The bearing part 3 j, axis supporting part 3 s, and lid part 3 u are manufactured by being injection molded with a synthetic resin such as polybutylene terephthalate (PBT), as is the manipulation body 11.

Next, the movable load imparting mechanism F5 of the manipulation device 100 will be described. FIG. 5 is an enlarged cross-sectional view of a portion V indicated in FIG. 4. FIG. 6A is a top perspective view of the movable load imparting mechanism F5, and FIG. 6B is a front view when viewed from the Y2 side indicated in FIG. 6A. FIG. 7A is a bottom perspective view in which a second yoke 25 illustrated in FIGS. 6A and 6B is omitted, and FIG. 7B is also a bottom perspective view in which the movable member 55 illustrated in FIG. 7A is further omitted.

The movable load imparting mechanism F5 includes the movable member 55, which operates by being engaged with the movable axis 11 j as illustrated in FIG. 4, the magnetism generating mechanism FM5, which faces one side of the movable member 55 with a gap 5 g intervening therebetween as illustrated in FIG. 5, and the magnetic viscous fluid 75 present in the gap 5 g. The magnetism generating mechanism FM5 in the movable load imparting mechanism F5 has a cylindrical shape as illustrated in FIG. 6A, and includes a coil 35 that generates a magnetic field by being energized, the first yoke 15 provided so as to enclose the coil 35, the second yoke 25 facing another side of the movable member 55 with the gap 5 g intervening therebetween, and a manipulation control part (not illustrated) that controls energization to the coil 35 as illustrated in FIG. 5. The movable load imparting mechanism F5 is structured so that upon receipt of a rotation manipulation by the manipulator, the movable load imparting mechanism F5 gives a load from the movable load imparting mechanism F5 to the manipulation body 11 to impart a rotational load to the manipulation part (such as a manipulation knob or a manipulation control) of the manipulation member 1 for the manipulator.

First, the magnetism generating mechanism FM5 in the movable load imparting mechanism F5 will be described. The coil 35 in the magnetism generating mechanism FM5 is formed by circularly winding a metal wire. As illustrated in FIG. 4, the coil 35 is disposed on one side (Z1 side indicated in FIG. 4) of the movable member 55. When the coil 35 is energized, a magnetic field is generated around the coil 35. Although the coil 35 has a shape in which a metal wire is wound and its turns are bound, the coil 35 in FIG. 2 has a flattened surface for simplicity.

The first yoke 15 in the magnetism generating mechanism FM5 is disposed so as to enclose the coil 35, as illustrated in FIG. 4. The first yoke 15 includes the upper yoke 15A, which covers one side (Z1 side indicated in FIG. 4) of the coil 35 and the inner side wall (side wall on the center side of the circular shape) of the coil 35, a transverse yoke 15B, which covers the outer side wall of the coil 35 and part of another side (Z2 side indicated in FIG. 4) of the coil 35, a lower yoke 15C, which covers part of the other side of the coil 35. The first yoke 15 is disposed on one side of the movable member 55 as illustrated in FIG. 5. Part of the transverse yoke 15B and the lower yoke 15C face the movable member 55 with the gap 5 g (specifically, a first gap 5 ga in FIG. 5) intervening therebetween. Due to this first yoke 15, a magnetic flux generated from the coil 35 is confined, so a magnetic field efficiently acts on the movable member 55.

As illustrated in FIGS. 5 and 7B, the first yoke 15 has a slit 15 s (yoke slit) defined by the transverse yoke 15B and lower yoke 15C on a side facing the movable member 55, so the first yoke 15 has a divided shape on the side facing the movable member 55. Now, a portion of the transverse yoke 15B, the portion facing the movable member 55, referred to as a first opposing part TB5 of the first yoke 15, and a portion of the lower yoke 15C, the portion facing the movable member 55, is referred to as a second opposing part TC5.

As illustrated in FIGS. 4 and 5, the width of this slit 15 s is smaller than the width of the gap 5 g (specifically, the first gap 5 ga) between the first yoke 15 and the movable member 55. Thus, when a magnetic field is generated due to energization to the coil 35, a magnetic path is formed so as to spread toward the movable member 55, for example, from the first opposing part TB5 of the first yoke 15 to its second opposing part TC5.

In the first embodiment of the present invention, the slit spacer S57 in a ring shape (see FIG. 2) is accommodated in the slit 15 s in the first yoke 15, as illustrated in FIG. 7B. This slit spacer S57 is formed by using a synthetic resin such as polybutylene terephthalate (PBT). In a magnetic circuit as well, the first opposing part TB5 of first yoke 15 (specifically, the horizontal yoke 15B) and the TC5 of the first yoke 15 (specifically, the lower yoke 15C) are separated from each other by the slit spacer S57. Although in the first embodiment of the present invention, the first yoke 15 is composed of three parts, upper yoke 15A, transverse yoke 15B and lower yoke 15C, this is not a limitation. The first yoke 15 may be composed of two parts or four or more parts. Although the first yoke 15 has a structure in which the slit 15 s is preferably used, the first yoke 15 may lack the slit 15 s.

The second yoke 25 in the magnetism generating mechanism FM5 is formed in a discoid shape as illustrated in FIG. 2. As illustrated in FIGS. 4, 5, and 6B, the second yoke 25 is preferably disposed on the other side of the movable member 55 and faces the movable member 55 with the gap 5 g (specifically, a second gap 5 gb in FIG. 5) intervening therebetween. Thus, the magnetic flux generated from the coil 35 reliably penetrates from the first opposing part TB5 of the first yoke 15 to the second yoke 25 and from the second yoke 25 to the second opposing part TC5 of the first yoke 15. Therefore, a magnetic path is reliably formed in a direction (Z direction perpendicular to an X-Y plane illustrated in FIG. 6B) perpendicular to a direction (direction crossing an X-Y plane illustrated in FIG. 6A) in which the movable member 55 operates.

The side-wall spacer S17, which forms part of the side wall of the main body, is formed between the outer periphery of the first yoke 15 (specifically, the transverse yoke 15B) and the outer periphery of the second yoke 25. This side-wall spacer S17 is also formed by using a synthetic resin such as polybutylene terephthalate (PBT). The first yoke 15 (specifically, the transverse yoke 15B) and the second yoke 25 are separated from each other by the side-wall spacer S17 in the magnetic circuit.

The first yoke 15, second yoke 25, and side-wall spacer S17 define a narrow accommodation space in directions (X-Y plane directions) orthogonal to the direction (Z direction illustrated in FIG. 4) along the movable axis 11 j of the manipulation body 11, as illustrated in FIG. 4. The movable member 55 in the movable load imparting mechanism F5 is disposed in this narrow accommodation space.

The manipulation control part in the magnetism generating mechanism FM5, which uses an integrated circuit (IC), controls the amount of energization to the coil 35, an energization timing, and the like. Specifically, when, for example, the manipulation body 11 is manipulated by the manipulator so as to rotate, upon reception of a detection signal from a position detecting means P6 that detects the manipulation position of the manipulation body 11, the manipulation control part causes a certain amount of current to flow into the coil 35 or changes the amount of current according to the manipulation position of the manipulation body 11.

The manipulation control part is mounted on a circuit board (not illustrated) and is electrically connected to the coil 35. Although the manipulation control part and circuit board are preferably disposed in the vicinity of the magnetism generating mechanism FM5, this is not a limitation. For example, the manipulation control part may be connected to the coil 35 through flexible printed circuits (FPC) or the like and may be mounted on a motherboard in an applicable product.

Next, the movable member 55 in the movable load imparting mechanism F5 will be described. The movable member 55 is preferably formed from a soft magnetic material such as iron, and is composed of a base part 55 d having a through-hole that has a center at the rotational center of the movable axis 11 j and a discoid part 55 e in a discoid shape, which is formed integrally with the base part 55 d and has a center at the rotational center, as illustrated in FIG. 2.

The base part 55 d of the movable member 55 is engaged with the movable axis 11 j of the manipulation body 11 at the lower part of the ring part 11 r of the manipulation body 11, as illustrated in FIG. 4. Thus, the discoid part 55 e of the movable member 55 rotationally moves in both directions along with the rotational operation of the manipulation body 11 in both directions.

When the manipulation device 100 has been assembled, the discoid part 55 e of the movable member 55 is accommodated in the narrow accommodation space described above, as illustrated in FIG. 4. Thus, the magnetic flux generated from the coil 35 reliably penetrates from the first opposing part TB5 of the first yoke 15 to the movable member 55, from the movable member 55 to the second yoke 25, from the second yoke 25 to the movable member 55, and from the movable member 55 to the second opposing part TC5 of the first yoke 15. Accordingly, a magnetic path is reliably formed in a direction perpendicular to the direction in which the movable member 55 operates.

In the discoid part 55 e, movable part slits 55 s in an arc shape are formed as illustrated in FIGS. 2 and 7A, the movable part slits 55 s resulting from dividing, into four parts, a virtual ring shape that has a center at the rotational center of the movable axis 11 j. Each movable part slit 55 s is formed at a position at which the movable part slit 55 s faces the slit 15 s formed in the first yoke 15, as illustrated in FIGS. 4 and 5. Thus, the magnetic flux generated from the coil 35 is not confined by the movable member 55; the magnetic flux can reliably penetrate to the second yoke 25 through the first yoke 15 and movable member 55 and from the second yoke 25 through the movable member 55 to the first yoke 15. Due to this, it is possible to lessen a magnetic flux that takes a shortcut so as to pass from the first yoke 15 through only the magnetic viscous fluid 75 on the upper side and the movable member 55 without being led to the second yoke 25 and then to be led to the first yoke 15 (from the transverse yoke 15B to the lower yoke 15C without passing through the second yoke 25).

In addition, since the width of the movable part slit 55 s is smaller than the width of the slit 15 s in the first yoke 15 as illustrated in FIG. 5, the movable member 55 can capture the spread of the magnetic flux from the first yoke 15, so the magnetic flux can be led to the second yoke 25. If a match is made between the center position of the width of the movable part slit 55 s and the center position of the slit 15 s, it is more preferable.

Next, the first buffering layer K16 and second buffering layer K26 in the manipulation device 100 will be described. The first buffering layer K16 in the manipulation device 100 is preferably formed from a synthetic resin sheet including magnetic powder, and is shaped like a flat plate, the shape being a circular shape having a through-hole 16 h at the center as illustrated in FIG. 2.

The first buffering layer K16 is disposed so as to be overlaid on the first yoke 15 (specifically, part of the transverse yoke 15B and the lower yoke 15C) positioned on the opposing plane of the movable member 55. Thus, it is possible to efficiently lead the magnetic flux generated from the coil 35 from the first yoke 15 to the movable member 55.

The first buffering layer K16 uses, as the magnetic powder, a material having hardness lower than that of the movable member 55, which is formed from a soft magnetic material such as iron, silicon steel, permalloy, or ferrite. Thus, even if the movable member 55 abuts the first yoke 15 when the movable member 55 operates, an abutting sound, a sliding sound, and the like are reduced. In addition, in the first embodiment of the present invention, since the base of the first buffering layer K16 is formed from a synthetic resin material having lower hardness, an abutting sound, a sliding sound, and the like are further reduced. Due to this, a more superior manipulation feeling can be given to the manipulator for a manipulation by the manipulator.

The second buffering layer K26 of the manipulation device 100 is preferably formed from a synthetic resin sheet including magnetic powder, and is shaped like a flat plate, the shape being a circular shape having a through-hole 26 h at the center as illustrated in FIG. 2, as with the first buffering layer K16.

The second buffering layer K26 is disposed so as to be overlaid on the second yoke 25 positioned on the opposing plane of the movable member 55. Thus, it is possible to efficiently lead the magnetic flux generated from the coil 35 to the movable member 55.

The second buffering layer K26 uses, as the magnetic powder, a material having hardness lower than that of the movable member 55, which is formed from a soft magnetic material such as iron, silicon steel, permalloy, or ferrite. Thus, even if the movable member 55 abuts the second yoke 25 when the movable member 55 operates, an abutting sound, a sliding sound, and the like are reduced. In addition, in the first embodiment of the present invention, since the base of the second buffering layer K26 is formed from a synthetic resin material having lower hardness, an abutting sound, a sliding sound, and the like are further reduced. Due to this, a more superior manipulation feeling can be given to the manipulator for a manipulation by the manipulator. The first buffering layer K16 can be easily disposed on the first yoke 15 by using an adhesive or the like to paste the first buffering layer K16 to the first yoke 15. Similarly, the second buffering layer K26 can be easily disposed on the second yoke 25 by using an adhesive or the like to paste the second buffering layer K26 to the second yoke 25.

Finally, the magnetic viscous fluid 75 in the movable load imparting mechanism F5 will be described. FIGS. 8A and 8B are each a schematic view illustrating the magnetic viscous fluid 75; FIG. 8A illustrates the magnetic viscous fluid 75 in a state in which a magnetic field is not applied, and FIG. 8B illustrates the magnetic viscous fluid 75 in a state in which a magnetic field is applied. In FIG. 8B, the flow of a magnetic field (magnetic flux) is illustrated by chain double-dashed lines for easy understanding of the explanation.

The magnetic viscous fluid 75 is a substance in which fine magnetic particles JR having magnetism, such as iron or ferrite, are dispersed in a solute SV including, for example, an organic solvent, as illustrated in FIG. 8A. The magnetic viscous fluid 75 is generally called the magneto rheological (MR) fluid. This magnetic viscous fluid 75 has the property that viscosity changes according to the strength of the magnetic field, and is distinguished from a similar magnetic fluid. A major difference in shape between them is the particle diameter of powder. The particle diameter of the MR fluid is about 1 μm to 1 mm. By comparison, the particle diameter of the magnetic fluid is about 10 nm to 1 μm. The particle diameter of the MR fluid is about 100 to 1000 times as large as the particle diameter of the magnetic fluid.

Here, the fact, in this magnetic viscous fluid 75, that viscosity changes according to the strength of the magnetic field will be briefly described.

When no magnetic field is applied to the magnetic viscous fluid 75, magnetic particles JR are irregularly dispersed in the solute SV as illustrated in FIG. 8A. In this case, if, for example, the movable member 55 operates (rotates on a plane (X-Y plane) perpendicular to the Z direction illustrated in FIG. 8A), the movable member 55 easily operates while receiving a relatively low resistive force.

If a current flows into the coil 35 in the magnetism generating mechanism FM5 and a magnetic field is generated, the magnetic particles JR are regularly arranged in a linearly chained state along the magnetic field acting on the magnetic viscous fluid 75, as illustrated in FIG. 8B (in FIG. 8B, arranged along the Z direction). The degree of this regularity changes according to the strength of the magnetic field. That is, the stronger the magnetic field acting on the magnetic viscous fluid 75 is, the higher the degree of regularity is. A stronger shearing force acts in a direction in which the regularity of the magnetic particles JR arranged in this linearly chained state is lost. As a result, viscosity in this direction is increased. In particular, the highest shearing force acts in a direction orthogonal to the magnetic field that has acted (in FIG. 8B, in an X-Y plane direction).

When the movable member 55 operates with the coil 35 energized as described above (in the state illustrated in FIG. 8B), a resistive force is exerted on the movable member 55. This resistive force (rotational load) is transmitted to the manipulation body 11 engaged with the movable member 55. Thus, the movable load imparting mechanism F5 can impart a rotational load (load due to rotation) in a rotation manipulation to the manipulator. In this case, since the manipulation control part controls the amount of energization to the coil 35, a timing at which to energize, and the like, an arbitrary load can be freely given to the manipulator at an arbitrary timing.

The result of verifying the fact that the resistive force (rotation load) becomes strong according to the strength of the magnetic field is illustrated in FIG. 9. FIG. 9 is a graph representing an example of a relationship between a current flowing in the coil 35 in the magnetism generating mechanism FM5 and torque applied to the manipulation body 11, with current (A) on the horizontal axis and torque (Nm) on the vertical axis. This torque is equivalent to the resistive force (rotation load) applied to the manipulation body 11.

As illustrated in FIG. 9, when the current that flows into the coil 35 in the magnetism generating mechanism FM5 becomes large, the generated magnetic field is strengthened accordingly. As this magnetic field becomes stronger, torque, that is, the resistive force (rotation load) applied to the manipulation body 11 is increased. On the basis of the fact that according to the strength of the magnetic field, viscosity changes and the resistive force is strengthened in the magnetic viscous fluid 75, as described above, a variable load can be applied to the manipulation body 11 (part of the manipulation member 1).

In the first embodiment of the present invention, the magnetic viscous fluid 75 having the property described above is preferably used. The magnetic viscous fluid 75 is disposed in the gap 5 g (specifically, the first gap 5 ga in FIG. 5) between the first yoke 15 and the movable member 55, as illustrated in FIG. 4. In particular, as illustrated in FIG. 5, the magnetic viscous fluid 75 is filled in the gap 5 g (specifically, the first gap 5 ga) between the movable member 55 and the first opposing part TB5 of the first yoke 15 and between the movable member 55 and the second opposing part TC5 of the first yoke 15. Thus, a rotational load is applied to the movable member 55, which operates in a direction crossing the magnetic flux formed from the first yoke 15 (specifically, the first opposing part TB5) to the movable member 55 and from the movable member 55 to the first yoke 15 (specifically, the second opposing part TC5), by the magnetic viscous fluid 75. Due to this, a rotational load is applied to the manipulation body 11 through the movable member 55 and movable axis 11 j. Accordingly, it is possible to provide the manipulation device 100 from which a superior manipulation feeling is obtained.

In addition, in the first embodiment of the present invention, there is a match between the area of a first opposing plane 15 r, illustrated in FIG. 7B, of the first opposing part TB5, the first opposing plane 15 r facing the magnetic viscous fluid 75, and the area of a second opposing plane 15 t, illustrated in FIG. 7B, of the second opposing part TC5, the second opposing plane 15 t facing the magnetic viscous fluid 75. Thus, magnetic flux densities become equivalent at the inlet and outlet of the magnetic flux. This enables the magnetic flux generated from the coil 35 to efficiently act in control of the viscosity of the magnetic viscous fluid 75. Due to this, it is possible to evenly impart a load (rotational load) to the movable member 55 and thereby give a more superior manipulation feeling to the manipulator.

Furthermore, in the first embodiment of the present invention, the magnetic viscous fluid 75 is also preferably filled in the gap 5 g (specifically, the second gap 5 gb) between the movable member 55 and the second yoke 25. The magnetic flux formed from the first yoke 15 (specifically, the first opposing part TB5) through the movable member 55 to the second yoke 25 and from the second yoke 25 through the movable member 55 to the first yoke 15 (specifically, the second opposing part TC5) also acts on the magnetic viscous fluid 75 filled in this gap 5 g (specifically, the second gap 5 gb). Therefore, magnetic particles JR can be aligned in a direction perpendicular to the direction in which the movable member 55 operates, so a stronger rotational load can be applied. Due to this, it is possible to impart a further rotational load, and even in an equivalent magnetic field, give a further large manipulation feeling to the manipulator.

In the first embodiment of the present invention, since the first buffering layer K16 is provided in the gap 5 g (specifically, the first gap 5 ga) between the first yoke 15 and the movable member 55, the fear about an abutting sound, a sliding sound, and the like in the operation of the movable member 55 is reduced. Thus, this gap 5 g (specifically, the first gap 5 ga) can be made narrower. The narrower this gap 5 g (specifically, the first gap 5 ga) is, the more strongly a rotational load can be applied. Due to this, even in an equivalent magnetic field, a further large manipulation feeling can be imparted to the manipulator according to an amount by which the gap 5 g (specifically, the first gap 5 ga) is narrowed.

Furthermore, in the first embodiment of the present invention, since the second buffering layer K26 is also provided between in the gap 5 g (specifically, the second gap 5 gb) between the second yoke 25 and the movable member 55, the fear about an abutting sound, a sliding sound, and the like in the operation of the movable member 55 is reduced. Thus, this gap 5 g (specifically, the second gap 5 gb) can also be made narrower. The narrower this gap 5 g (specifically, the second gap 5 gb) is, the more strongly a rotational load can be applied. Due to this, even in an equivalent magnetic field, a further large manipulation feeling can be imparted to the manipulator according to an amount by which the gap 5 g (specifically, the second gap 5 gb) is narrowed.

The manipulation device 100, structured as described above, in the first embodiment of the present invention does not use the motor 810 to impart an external force (sense of force) such as a resistance force or thrust that matches the amount of manipulation of the manipulation member 1 and its manipulation direction. This is unlike the first conventional example. Therefore, it is possible to perform downsizing and reduce power consumption. In addition, a sound is not generated when an external force (sense of force) is imparted.

Finally, the effects of the manipulation device 100 in the first embodiment of the present invention will be compiled below.

The manipulation device 100 in the first embodiment of the present invention has included the movable member 55, which operates by being engaged with the movable axis 11 j of the manipulation body 11, the coil 35 and first yoke 15 in the magnetism generating mechanism FM5 disposed on one side of the movable member 55, and the magnetic viscous fluid 75 filled in the gap 5 g (specifically, the first gap 5 ga) between the first yoke 15 and the movable member 55. Thus, a magnetic field is generated by energization to the coil 35, a magnetic path is formed so as to spread from the first yoke 15 toward the movable member 55, and thereby magnetic particles JR in the magnetic viscous fluid 75 are aligned along the magnetic flux. Therefore, a rotational load is applied to the movable member 55, which operates in a direction crossing the magnetic flux formed from the first yoke 15 to the movable member 55 and from the movable member 55 to the first yoke 15, by the magnetic viscous fluid 75. Due to this, a rotational load is applied to the manipulation body 11 through the movable member 55 and movable axis 11 j. Even if the movable member 55 abuts the first yoke 15 when the movable member 55 operates, an abutting sound, a sliding sound, and the like are reduced because at least one of the first yoke 15 and movable member 55 has the first buffering layer K16 having hardness lower than that of the movable member 55. Due to these, a superior manipulation feeling can be given to the manipulator for a manipulation by the manipulator.

Since the movable member 55 is preferably formed from a soft magnetic material, a magnetic path is reliably formed from the first yoke 15 (specifically, the first opposing part TB5) to the movable member 55 and from the movable member 55 to the first yoke 15 (specifically, the second opposing part TC5) and thereby magnetic particles JR in the magnetic viscous fluid 75 are aligned in an opposing plane direction (Z direction indicated in FIG. 4) in which the first yoke 15 and movable member 55 face each other. Thus, a stronger rotational load is applied to the movable member 55, which operates in a direction crossing the opposing plane direction in which the magnetic particles JR are aligned. Due to this, a stronger rotational load is applied to the manipulation body 11 through the movable member 55 and movable axis 11 j and a more superior manipulation feeling can be given to the manipulator.

Since the magnetism generating mechanism FM5 preferably has the second yoke 25 disposed so as to face the other side of the movable member 55, a magnetic path is reliably formed from the first yoke 15 (specifically, the first opposing part TB5) to the second yoke 25 and from the second yoke 25 to the first yoke 15 (specifically, the second opposing part TC5). Thus, magnetic particles JR can be aligned in a direction perpendicular to the direction in which the movable member 55 operates, so a stronger load (rotational load) can be applied. Due to this, a stronger rotational load can be applied to the manipulation body 11 through the movable member 55 and movable axis 11 j.

Since the magnetic viscous fluid 75 is preferably filled in the gap 5 g (specifically, the second gap 5 gb) between the movable member 55 and the second yoke 25, a further rotational load can be imparted to the movable member 55, which operates in a direction crossing the magnetic flux. Due to this, even in an equivalent magnetic field, a further large manipulation feeling can be given to the manipulator.

Since the first buffering layer K16 is preferably formed from a synthetic resin sheet including magnetic powder, the magnetic flux generated from the coil 35 can be led from the first yoke 15 to the movable member 55, so a further load can be imparted to the movable member 55, which operates in a direction crossing the magnetic flux. In addition, since the base of the first buffering layer K16 is formed from a synthetic resin material having lower hardness, an abutting sound, a sliding sound, and the like are further reduced. Due to these, a more superior manipulation feeling can be given to the manipulator for a manipulation by the manipulator.

Since at least one of the second yoke 25 and movable member 55 preferably has the second buffering layer K26 having hardness lower than that of the movable member 55, even if the movable member 55 abuts the second yoke 25 when the movable member 55 operates, an abutting sound, a sliding sound, and the like are reduced. Due to this, a superior manipulation feeling can be given to the manipulator for a manipulation by the manipulator.

Since the second buffering layer K26 is preferably formed from a synthetic resin sheet including magnetic powder, the magnetic flux generated from the coil 35 can be led from the first yoke 15 to the second yoke 25, so a further load can be imparted to the movable member 55, which operates in a direction crossing the magnetic flux. In addition, since the base of the second buffering layer K26 is formed from a synthetic resin material having lower hardness, an abutting sound, a sliding sound, and the like are further reduced. Due to these, a more superior manipulation feeling can be given to the manipulator for a manipulation by the manipulator.

The present invention is not limited to the embodiment described above. The present invention can also be practiced by, for example, making variations as described below. These variations are also included in the technical range of the present invention.

First Variation

Although, in the first embodiment described above, the magnetic viscous fluid 75 has been supplied so as to fill the accommodation space in which the movable member 55 is accommodated (accommodation space defined by the first yoke 15, second yoke 25, and side-wall spacer S17), this is not a limitation; the magnetic viscous fluid 75 only needs to be present in at least part of the gap 5 g.

Second Variation, Third Variation, and Fourth Variation

Although, in the first embodiment described above, a structure in which the first buffering layer K16 is disposed on the first yoke 15 has been taken, the first buffering layer K16 only needs to be provided on at least one of the first yoke 15 and movable member 55. For example, a structure in which the first buffering layer K16 is provided on the movable member 55 may also be taken as a second variation. Similarly, although the structure in which the second buffering layer K26 is disposed on the second yoke 25 has been taken, the second buffering layer K26 only needs to be provided on at least one of the second yoke 25 and movable member 55. For example, a structure in which the second buffering layer K26 is provided on the movable member 55 may also be taken as a third variation. Alternatively, a structure in which the second variation and fourth variation are combined may be taken as a fourth variation.

Fifth Variation

Although, in the first embodiment described above, the movable member 55 has been preferably formed from a soft magnetic material, this is not a limitation; the movable member 55 may be formed from a non-magnetic material such as a synthetic resin.

Sixth Variation and Seventh Variation

Although, in the first embodiment described above, a synthetic resin sheet including magnetic powder has been preferably used to form the first buffering layer K16, this is not a limitation; a magnetic sheet having hardness lower than that of the movable member 55 to be used may be used as a sixth variation. Thus, the magnetic flux generated from the coil 35 can be led from the first yoke 15 to the movable member 55. Similarly, instead of preferably using a synthetic resin sheet including magnetic powder to form the material of the second buffering layer K26, a magnetic sheet having hardness lower than that of the movable member 55 to be used may be used as a seventh variation. Thus, the magnetic flux generated from the coil 35 can be led from the first yoke 15 to the second yoke 25.

Eighth Variation and Ninth Variation

Although, in the first embodiment described above, a synthetic resin sheet including magnetic powder has been preferably used to form the first buffering layer K16, this is not a limitation; a synthetic resin sheet having hardness lower than that of the movable member 55 to be used may be used as an eighth variation. Similarly, instead of preferably using a synthetic resin sheet including magnetic powder to form the second buffering layer K26, a synthetic resin sheet having hardness lower than that of the movable member 55 to be used may be used as a ninth variation. Materials of the synthesis resin to be substituted include, for example, a polyethylene terephthalate resin (PET), a polyimide resin (PI), a polyamide resin (PA), a poly ether ether ketone resin (PEEK), a polytetrafluoroethylene resin (PTFE), a polyethylene resin (PE), a polytetrafluoroethylene resin (PEN), a poly phenylene sulfide resin (PPS), and the like.

Tenth Variation and Eleventh Variation

Although, in the first embodiment described above, a synthetic resin sheet including magnetic powder has been preferably used to form the first buffering layer K16 and second buffering layer K26, this is not a limitation; a synthetic rubber material having hardness lower than that of the movable member 55 to be used may be used as a tenth variation. Alternatively, a plated coating, such as a tin-plated coating, that has hardness lower than that of the movable member 55 to be used may be used as an eleventh variation.

Twelfth Variation

Although, in the first embodiment described above, the transverse yoke 15B of the first yoke 15 has had the first opposing part TB5 and the lower yoke 15C of the first yoke 15 has had the second opposing part TC5, a structure may be taken in which only the lower yoke 15C faces the movable member 55 and the first opposing part TB5 and second opposing part TC5 are not provided.

Thirteenth Variation

Although, in the first embodiment described above, the movable member 55 has included a discoid shape, this is not a limitation; for example, the movable member 55 may have a rectangular shape or a polygonal shape.

Fourteenth Variation

Although, in the first embodiment described above, a structure in which the movable part slits 55 s are formed in the movable member 55, which is preferably formed from a soft magnetic material, has been taken, a structure in which the movable part slits 55 s are not formed may be used. In that case, the movable member 55 is preferably formed from a non-magnetic material.

Fifteenth Variation and Sixteenth Variation

Although, in the first embodiment described above, the manipulation device has been of a rotational type in which the movable member 55 rotationally operates, the operation is not limited to this rotational operation. As a fifteenth variation, the manipulation device may be, for example, of a slide type in which the movable member 55 performs a slide operation in a direction crossing the direction in which the support body 3 extends. Alternatively, as a sixteenth variation, the manipulation device may be, for example, of a push type in which the movable member 55 performs a push operation in the direction in which the support body 3 extends. When the manipulation device is of a slide type, if the movable member 55 and first yoke 15 (and second yoke 25) face each other in a direction crossing (preferably, orthogonal to) the push operation direction and the magnetic viscous fluid 75 is filled in the gap 5 g between the movable member 55 and the first yoke 15 (and between the movable member 55 and the second yoke 25), a load can be appropriately given.

The present invention is not limited to the above embodiment. The present invention can be appropriately modified without departing from the intended scope of the present invention. 

What is claimed is:
 1. A manipulation device comprising: a manipulation member including a manipulation body having a movable axis that allows an operation of the manipulation member in a manipulation direction according to a manipulation by a manipulator; a support body that supports the manipulation body movably in the manipulation direction; and a bias mechanism that applies a movable load to the manipulation body, the bias mechanism including: a movable member that operates by engaging with the movable axis of the manipulation body; a magnetism generating mechanism that faces the movable member with a gap provided therebetween, the magnetism generating mechanism including a coil that generates a magnetic field by being energized, and a first yoke disposed on one side of the movable member as to enclose the coil; a magnetic viscous fluid provided in the gap, the magnetic viscous fluid filling a first part of the gap between the first yoke and the movable member, viscosity of the magnetic viscous fluid changing according to a strength of the magnetic field thereby applying a corresponding load onto the movable member; and a first buffering layer provided in the gap and disposed on at least one of a surface of the first yoke and a first surface of the movable member facing the surface of the first yoke, the first buffering layer being formed of a synthetic resin sheet including magnetic powder.
 2. The manipulation device according to claim 1, wherein the movable member is formed of a soft magnetic material.
 3. The manipulation device according to claim 1, wherein the magnetism generating mechanism has a second yoke disposed on another side of the movable member so as to face the movable member.
 4. The manipulation device according to claim 3, wherein the magnetic viscous fluid also fills a second part of the gap between the second yoke and the movable member.
 5. The manipulation device according to claim 1, wherein the magnetic powder of the first buffering layer has hardness lower than hardness of the movable member.
 6. The manipulation device according to claim 3, wherein at least one of the second yoke and the movable member has a second buffering layer having hardness lower than hardness of the movable member.
 7. The manipulation device according to claim 6, wherein the second buffering layer is formed of a magnetic sheet.
 8. The manipulation device according to claim 6, wherein the second buffering layer is a synthetic resin sheet including magnetic powder.
 9. The manipulation device according to claim 1, wherein the movable member is disk-shaped and rotates in a plane substantially parallel to the first surface thereof and perpendicular to the movable axis, wherein the first yoke has a bottom surface facing the first surface via the gap, and wherein the magnetism generating mechanism is configured to generate a magnetic flux substantially perpendicular to the bottom surface of the first yoke and the first surface of the movable member across the gap filled with the magnetic viscous fluid.
 10. The manipulation device according to claim 9, wherein the first buffering layer allows to reduce the gap between the bottom surface and the first surface by reducing sound of abutting or sliding of the movable member against the first yoke by intervening therebetween.
 11. A manipulation device comprising: a manipulation member including a manipulation body having a movable axis that allows an operation of the manipulation member in a manipulation direction according to a manipulation by a manipulator; a support body that supports the manipulation body movably in the manipulation direction; and a bias mechanism that applies a movable load to the manipulation body, the bias mechanism including: a movable member that operates by engaging with the movable axis of the manipulation body; a magnetism generating mechanism that faces the movable member with a gap provided therebetween, the magnetism generating mechanism including a coil that generates a magnetic field by being energized, and a first yoke disposed on one side of the movable member as to enclose the coil; a magnetic viscous fluid provided in the gap, the magnetic viscous fluid filling a first part of the gap between the first yoke and the movable member, viscosity of the magnetic viscous fluid changing according to a strength of the magnetic field thereby applying a corresponding load onto the movable member; and a first buffering layer provided in the gap and disposed on at least one of a surface of the first yoke and a first surface of the movable member facing the surface of the first yoke, the first buffering layer being formed of a magnetic sheet having hardness lower than hardness of the movable member, thereby reducing sound of abutting or sliding of the movable member against the first yoke by intervening therebetween.
 12. A manipulation device comprising: a manipulation member including a manipulation body having a movable axis that allows an operation of the manipulation member in a manipulation direction according to a manipulation by a manipulator; a support body that supports the manipulation body movably in the manipulation direction; and a bias mechanism that applies a movable load to the manipulation body, the bias mechanism including: a movable member that operates by engaging with the movable axis of the manipulation body; a magnetism generating mechanism including: a coil that generates a magnetic field by being energized; a first yoke disposed on one side of the movable member as to enclose the coil, the first yoke facing a first surface of the movable member with a first gap provided therebetween; and a second yoke disposed on another side of the movable member and facing a second surface of the movable member with a second gap provided therebetween; a magnetic viscous fluid provided in and filling the first and second gaps, viscosity of the magnetic viscous fluid changing according to a strength of the magnetic field thereby applying a corresponding load onto the movable member; and a first buffering layer provided in the first gap and disposed on at least one of the first surface of the movable member and a surface of the first yoke facing the first surface; a second buffering layer provided in the second gap and disposed on at least one of the second surface of the movable member and a surface of the second yoke facing the second surface, wherein each of the first and second buffering layers are formed of a synthetic resin sheet including magnetic powder.
 13. The manipulation device according to claim 12, wherein the movable member is formed of a soft magnetic material.
 14. The manipulation device according to claim 13, wherein the magnetic powder of the first and second buffering layers has hardness lower than hardness of the movable member. 